Organic light-emitting diode (oled) display and method of manufacturing the same

ABSTRACT

An organic light-emitting diode (OLED) display is disclosed. In one aspect, the OLED display includes a substrate, a plurality of sub-pixels over the substrate, wherein each of the plurality of sub-pixels includes an OLED layer comprising an OLED, wherein the OLED comprises a first electrode, a second electrode facing the first electrode, and an emitting layer therebetween, an encapsulation layer over the OLED layer and comprising at least one inorganic layer and at least one organic layer, a refractive layer comprising a first refractive index layer that is located over the encapsulation layer and has a recess and a second refractive index layer that is located over the first refractive index layer, wherein the second refractive index is greater than the first refractive index, and wherein an upper surface of the refractive layer is flat.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/116,844, filed Aug. 29, 2018, which is a continuation of U.S. patentapplication Ser. No. 15/219,076, filed Jul. 25, 2016, now U.S. Pat. No.10,084,024, which is a continuation of U.S. patent application Ser. No.14/639,808 filed on Mar. 5, 2015, now U.S. Pat. No. 9,406,724, whichclaims priority to and the benefit of Korean Patent Application No.10-2014-0100705, filed Aug. 5, 2014, the entire content of all of whichis incorporated herein by reference.

BACKGROUND Field

The described technology generally relates to an organic light-emittingdiode (OLED) display and a method of manufacturing the same.

Description of the Related Technology

Since an OLED display is self-emissive, it can operate at a low voltageand can be lightweight and thin. In addition, OLED technology has drawnattention as a next generation display because of its favorablecharacteristics such as wide viewing angles, a high contrast and fastresponse speed. The OLED display implements full colors by using threecolors of light, for example, red, green and blue. To implementhigh-quality colors regardless of viewing angles of a user, an OLEDdisplay which has good light efficiency and wide side viewing anglesneeds to be implemented.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

One inventive aspect is an OLED display and a method of manufacturingthe same.

Another aspect is an OLED display which includes: an organiclight-emitting device including a plurality of pixels which emitdifferent colors of light; an encapsulation layer formed on the organiclight-emitting device; a color filter layer formed on an upper surfaceof the encapsulation layer and including color filters which are formedon areas corresponding to the plurality of pixels and light block unitswhich are respectively formed between the color filters; and an edgelens unit formed on a lower surface of the color filter layer and formedbetween a lower surface of each of the color filter and a lower surfaceof each of the light block unit.

The edge lens unit may include at least one edge lens which is convex ina direction opposite to a light emission direction.

A bonding area where the encapsulation layer and the color filter layermay be bonded to each other is filled with air.

The edge lens unit may be formed of an organic material having arefractive index that is higher than a refractive index of air.

The bonding area where the encapsulation layer and the color filterlayer are bonded to each other may be filled with an organic materialhaving a low refractive index.

The edge lens unit may be filled with an organic material having arefractive index that is higher than the refractive index of the organicmaterial filling the bonding area.

The edge lens may be formed on edges of the light block unit and some ofthe color filters.

The at least one edge lens may have a polygonal shape having two or morefacets according to a shape of each of the pixels.

The height of the at least one edge lens may be in a range from about 1to about 5 micrometers.

The width of the at least one edge lens may be between 2 micrometers andhalf of the width of one of the color filters.

An initial angle of the at least one edge lens may be in a range fromabout 40 to about 90 degrees.

Another aspect is an OLED display which includes: an organiclight-emitting device including a plurality of pixels which emitdifferent colors of light; an encapsulation layer formed on the organiclight-emitting device; a color filter layer including color filtersformed on areas corresponding to pixels and light block unitsrespectively formed between the color filters; and edge lens unitsformed on a lower surface of the color filter layer and formed betweenlower surfaces of the color filters and those of the light block units.

The light diffusion lens unit may include at least one light diffusionlens which is formed on each of the color filters and is convex in alight emission direction.

The edge lens unit and the light diffusion lens unit may be formed of anorganic material having a small refractive index.

The height of the at least one light diffusion lens may be equal to orgreater than 1 micrometer.

The width of the at least one light diffusion lens may be between 2micrometers and a third of the width of one of the color filters.

The light diffusion lens unit may be formed on each of the color filtersand include two or more light diffusion lenses which are formed in eachof the color filters and convex in a light emission direction.

Another aspect is a method of manufacturing an OLED display, whichincludes: forming, on a substrate, organic light-emitting devices whichcomprise a plurality of sub-pixels emitting different colors of light;forming an encapsulation layer which encapsulates the organiclight-emitting devices; forming a color filter layer comprising colorfilters which are formed on areas corresponding to the plurality ofsub-pixels and light block units which are respectively formed betweenthe color filters; forming edge lens units on a lower surface of thecolor filter layer and between lower surfaces of the color filters andlower surfaces of the light block unit; and bonding the color filterlayer, which has the lower surface on which the edge lens units areformed, to the organic light-emitting devices which are formed on thesubstrate and encapsulated by an encapsulation layer.

In the bonding, a bonding area where the color filter layer is bonded tothe encapsulation layer may be in an air state.

In the bonding, a bonding area where the color filter layer is bonded tothe encapsulation layer may be filled with an organic material having alow refractive index. In the bonding, the color filter layer may bebonded to the encapsulation layer in the bonding area by at least one ofan on drop filling (ODF) process and an encapsulation process.

Another aspect is an organic light-emitting diode (OLED) displaycomprising: an OLED comprising a plurality of pixels configured to emitdifferent colors of light; an encapsulation layer formed over the OLED;a color filter layer formed over the encapsulation layer, wherein thecolor filter layer comprises a plurality of color filters formed onregions corresponding to the pixels and a plurality of light block unitsrespectively formed at least between the color filters; and an edge lensunit formed at least between a lower surface of each of the colorfilters and a lower surface of each of the light block units.

In the above display, the edge lens unit comprises at least one edgelens convex toward the encapsulation layer. In the above display, abonding area where the encapsulation layer and the color filter layerare bonded to each other is substantially filled with air. In the abovedisplay, the edge lens unit is formed of an organic material having arefractive index higher than the refractive index of air. In the abovedisplay, the bonding area is substantially filled with an organicmaterial having a low refractive index. In the above display, the edgelens unit is substantially filled with an organic material having arefractive index higher than the refractive index of the organicmaterial filling the bonding area. In the above display, the at leastone edge lens is formed on an edge portion of a black matrix and colorfilters adjacent to the edge portion of the black matrix from among thecolor filters.

In the above display, the at least one edge lens has a polygonal shapehaving a plurality of facets according to a shape of each of the pixels.In the above display, the height of the at least one edge lens is in arange from about 1 micrometers to about 5 micrometers. In the abovedisplay, the width of the at least one edge lens is between about 2micrometers and half of the width of one of the color filters. In theabove display, an initial angle of the at least one edge lens is in arange from about 40 degrees to about 90 degrees, and wherein the initialangle is measured with respect to a lower surface of the color filterlayer. The above display further comprises a light diffusion lens unitformed over the color filter layer. In the above display, the lightdiffusion lens unit comprises at least one light diffusion lens formedover each of the color filters and shaped to be convex toward theencapsulation layer.

In the above display, the edge lens unit and the light diffusion lensunit are formed of an organic material. In the above display, the heightof the at least one light diffusion lens is greater than or equal toabout 1 micrometer. In the above display, the width of the at least onelight diffusion lens is between about 2 micrometers and about a third ofthe width of one of the color filters. In the above display, the lightdiffusion lens unit is formed on each of the color filters and comprisesa plurality of light diffusion lenses formed in each of the colorfilters and convex toward the encapsulation layer.

Another aspect is a method of manufacturing an organic light-emittingdiode (OLED) display, the method comprising: forming, over a substrate,an OLED comprising a plurality of pixels configured to emit differentcolors of light; forming an encapsulation layer which encapsulates theOLEDs; forming a color filter layer comprising a plurality of colorfilters formed on regions corresponding to the pixels and a plurality oflight block units respectively formed at least between the colorfilters; forming an edge lens unit at least between lower surfaces ofthe color filters and lower surfaces of the light block units; andbonding the color filter layer to the OLED.

In the above method, a bonding area where the color filter layer isbonded to the encapsulation layer is in an air state. In the abovemethod, a bonding area where the color filter layer is bonded to theencapsulation layer is substantially filled with an organic materialhaving a low refractive index. In the above method, the color filterlayer is bonded to the encapsulation layer in the bonding area by atleast one of an on drop filling (ODF) process and an encapsulationprocess.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of an OLED display accordingto an embodiment.

FIG. 2 is a diagram of an enlarged portion of the OLED display of FIG.1.

FIG. 3 is a diagram of an organic light-emitting device of FIG. 1 whichcorresponds to one sub-pixel area.

FIG. 4 is a schematic diagram of an OLED display according to anotherembodiment.

FIG. 5 is a diagram of an enlarged portion of the OLED display of FIG.4.

FIG. 6 is a schematic diagram of an OLED display according to anotherembodiment.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

While such terms as “first”, “second”, etc., may be used to describevarious components, such components must not be limited to the aboveterms. The above terms are used only to distinguish one component fromanother.

The terms used in the present specification are merely used to describeparticular embodiments, and are not intended to limit the presentinvention. An expression used in the singular encompasses the expressionof the plural, unless it has a clearly different meaning in the context.In the present specification, it is to be understood that the terms suchas “including”, “having”, and “comprising” are intended to indicate theexistence of the features, numbers, steps, actions, components, parts,or combinations thereof disclosed in the specification, and are notintended to preclude the possibility that one or more other features,numbers, steps, actions, components, parts, or combinations thereof mayexist or may be added. In this disclosure, the term “substantially”includes the meanings of completely, almost completely or to anysignificant degree under some applications and in accordance with thoseskilled in the art. Moreover, “formed on” can also mean “formed over.”The term “connected” includes an electrical connection.

Hereinafter, embodiments will be described in detail with reference tothe attached drawings. Like reference numerals in the drawings denotelike elements.

FIG. 1 is a schematic cross-sectional view of an OLED display accordingto an embodiment, and FIG. 2 is a diagram of an enlarged portion of theOLED display of FIG. 1. FIG. 3 is a diagram of an organic light-emittingdevice or OLED 200 of FIG. 1 which corresponds to one sub-pixel area.

Referring to FIG. 1, the OLED display includes a substrate 100, organiclight-emitting devices 200 formed on the substrate 100, an encapsulationlayer 300, a color filter layer 400, and edge lens units 500.

The substrate 100 may be formed of plastic having a good heat resistanceand durability. However, the substrate 100 may be formed of variousmaterials such as metals and glass.

The organic light-emitting device 200 is formed on the substrate 100 andmay include sub-pixels P1, P2 and P3 emitting different colors of light.As an exemplary embodiment, a display device 200 may be an organiclight-emitting device including a first sub-pixel P1 which emits bluelight, a second sub-pixel P2 which emits green light, and a thirdsub-pixel P3 which emits red light.

Referring to FIG. 3, the organic light-emitting device 200 may include abuffer layer 201 which is formed on the substrate 100 and substantiallyblocks impurities and moisture, a thin film transistor (TFT) 210 formedon the buffer layer 201, a first electrode 221 which is connected to theTFT 210, a second electrode 223 which is opposite to the first electrode221, an intermediate layer 222 which is interposed between the first andsecond electrodes 221 and 223 and includes an emission layer.

The TFT 210 may include an active layer 211, a gate electrode 212,source electrode 213 s, and a drain electrode 213 d. A first insulatinglayer 202 may be interposed between the gate electrode 212 and theactive layer 211 as a gate insulating layer in order to insulate thegate electrode 212 and the active layer 211 from each other. The activelayer 211 may include a channel area formed at the center thereof andsource and drain areas formed on both sides of the channel area. Theactive layer 211 may include amorphous silicon, crystalline silicon, oran oxide semiconductor.

The source and drain areas may be formed when the gate electrode 212 isdoped with highly concentrated impurities by using a self-align mask. InFIG. 3, a top-gate type TFT 210 is illustrated, but is not limitedthereto. As another example, a bottom-gate type TFT may be used.

The source and drain electrodes 213 s and 213 d are formed on the gateelectrode 212 by interposing a second insulating layer 203 between thesource and drain electrodes 213 s and 213 d. The source and drainelectrodes 213 s and 213 d may be electrically connected to the sourceand drain areas, respectively. A third insulating layer 204 may beformed on the source and drain electrodes 213 s and 213 d.

Any one of the source and drain electrodes 213 s and 213 d may beelectrically connected to the first electrode 221, and the intermediatelayer 222 including the emission layer, and the second electrode 223 maybe formed on the first electrode 221.

As shown in FIG. 3, each of the sub-pixels P1, P2 and P3 has theabove-described structure, and the emission layer included in theintermediate layer 222 of each of the sub-pixels P1, P2 and P3 includesorganic materials which emit red, green, and blue light. The emissionlayer emitting red, green, and blue light may include a low molecularweight organic material or a polymer organic material. According totypes of the organic light-emitting layer, the intermediate layer 222may further include at least one of a hole transport layer, a holeinjection layer, an electron transport layer, and an electron injectionlayer.

Referring back to FIG. 1, the encapsulation layer 300 is formed on theorganic light-emitting device 200 and protects the organiclight-emitting device 200 from impurities and/or external air. Theencapsulation layer 300 may be formed right above the organiclight-emitting device 200 and may be a thin-film encapsulation layer inwhich an organic layer and an inorganic layer are alternately stacked.The organic layer may include an acryl-based resin, an epoxy-basedresin, and a polymer-based resin such as polyimide and polyethylene, andthe inorganic layer may include metal oxide, metal nitride, metalcarbide, and a combination thereof.

The color filter layer 400 is formed on the encapsulation layer 300 andmay include color filters 410 formed on areas corresponding to thesub-pixels P1, P2 and P3 and light block units 430 respectively formedbetween the color filters 410 (or formed on areas corresponding to areasbetween the sub-pixels P1, P2 and P3). Since an extremely small amountof external light that is incident onto the colors filters 410 isreflected, external light visibility and definition of an image may beimproved. The light block units 430 formed on the areas between thesub-pixels P1, P2 and P3, that is, non-emissive areas, are used toreduce contrast resulting from bottom reflection of the external lightand may include a black matrix which absorbs light of a wavelength ofvisible spectrum. The bottom reflection means that light is reflectedfrom electrodes or wiring layers of the organic light-emitting device200 or the substrate 100 formed under the organic light-emitting device200.

The OLED display according to the present embodiment may further includeedge lens units 500 formed under the color filter layer 400, as shown inFIG. 1.

Each of the edge lens units 500 may include one or more edge lenses, andin particular, the edge lenses may be respectively formed on a lowersurface of the color filter layer 400 and may be respectively formedbetween lower surfaces of the light block units 430 adjacent to thecolor filters 410. Each of the edge lenses may be formed of an organicmaterial having a high refractive index.

As shown in FIG. 1, each edge lens may protrude on a lower surface ofthe color filter layer 400 in a direction opposite to a light emissiondirection. That is, each of the edge lenses may protrude toward thesubstrate 100.

Also, there may be one or more edge lenses, and the edge lenses may berespectively formed between the lower surfaces of the light block units430 adjacent to the color filters 410, as shown in FIG. 1. That is, eachlens unit 500 may be formed to include six edge lenses in one sub-pixel.However, the number of edge lenses is not limited thereto.

That is, each of the edge lens units 500 has a convex shape and isformed on the lower surface of the color filter layer 400. Thus, theedge lens units 500 may be respectively formed between the lowersurfaces of the color filters 410 and the lower surfaces of the lightblock units 430 adjacent to the color filters 410. As a result, overallefficiency of the organic light-emitting devices 200 is improved, and aproblem regarding viewing angles may be corrected due to the edge lensunits 500. A form, materials, and functions of the edge lens units 500will be described in detail later.

The OLED display according to the present embodiment has an advantage inthat the edge lens units 500 are respectively formed between the lowersurfaces of the light block units 430 adjacent to the color filters 410,thereby effectively emitting light.

That is, light emitted from the organic light-emitting devices 200passes edge lenses formed on the lower surface of the color filter layer400 and may pass toward the viewing angles of a user because the edgelenses are formed between the lower surfaces of the color filters 410and those of the light block units 430. In the case of light which issubstantially straightly emitted toward a center, although theefficiency of the light may be low, the efficiency of the organiclight-emitting devices may be generally improved, and the viewing anglesmay also be improved.

As shown in FIG. 1, a bonding layer 600, which is formed between thecolor filter layer 400 under which the edge lens units 500 are formedand the substrate 100 on which the organic light-emitting devices 200are formed, may be formed by being substantially filled with a materialhaving a low refractive index.

When the boding unit 600 is formed of the material having the lowrefractive index, refractive indices of the edge lens units 500 and thebonding area 600 are increased, and thus, reflection of external lightis decreased.

That is, when light is from the outside, external light penetratessub-pixel areas and then is reflected from the same. In this case, ifthe light is curved toward the light block units 430 by using adifference between the refractive indices, the light is absorbed by thelight block units 430, and thus, reflection of the external light may bedecreased.

In the OLED display according to the present embodiment, an area betweenthe encapsulation layer 300 and the color filter layer 400 may besubstantially filled with air. That is, when a substrate layer, on whichan upper surface of the color filter layer 400 and a lower surface ofthe encapsulation layer 300 are formed, is bonded in a vacuum state, thebonding area 600 may be in an air state.

A refractive index of the air is 1.0, and the edge lens units 500 may beformed of a material having a refractive index higher than therefractive index of the air. Accordingly, when external light is fromthe outside, since the edge lenses are convex and a refractive index ofthe edge lenses are higher than those of neighboring components, thelight may be refracted outward.

The bonding area 600 which bonds the area between the color filter layer400 and the encapsulation layer 300 may be substantially filled with amaterial having a low refractive index.

In this embodiment, since the bonding area 600 is substantially filledwith the material having the low refractive index, the edge lenses mayhave the refractive index higher than the refractive index of theorganic material which fills the bonding area 600.

Furthermore, since the refractive index of the edge lenses is higherthan that of the organic material which is formed on a lower portion,light emitted from the organic light-emitting device 200 may beeffectively extracted.

Therefore, as the edge lenses having the high refractive index areformed between the lower surfaces of the color filters 410 and those ofthe light block units 430 and bottom portions of the edge lenses aresubstantially filled with an organic material having a low refractiveindex or air, light efficiency is improved. In addition, since the usermay watch an entire screen even when the user watches the screen at aside, the viewing angles are improved.

FIG. 2 shows one color filter 410 corresponding to a pixel, the lightblock unit 430 corresponding to the color filter 410, and one edge lensunit 500 in detail.

As shown in FIGS. 1 and 2, the edge lenses may be formed on edges of thelight block units 430.

In some embodiments, the edge lenses are not separately formed in eachcolor filter area, and some of the edge lenses may be formed on thelight block units 430 and the other of the edge lenses are formed on thecolor filters 410.

As the edge lenses are formed on the lower surfaces of the color filters410 and those of the light block units 430 adjacent to the color filters410, the number of edge lenses formed on the lower surfaces of the colorfilters 410 and those of the light block units 430 adjacent to the colorfilters 410 may be greater than the number of edge lenses formed only onthe lower surfaces of the color filters 410.

In some embodiments, when the edge lenses are formed only on the lowersurfaces of the color filters 410, the edge lens may be respectivelyformed on the lower surfaces of the color filters 410. When some of theedge lenses are formed on the edges of the light block units 430 and theother of the edge lenses are formed on the lower surfaces of the colorfilters 410, two edge lenses may be formed on each of the lower surfacesof color filter 410 as shown in FIG. 2.

Therefore, the maximum number of edge lenses that may be included in theedge lens unit 500 is increased, and accordingly, refraction of lightmay be great when external light enters. That is, the efficiency of theOLED display is improved, and side visibility may be improved.

According to shapes of the color filters 410, the edge lenses may have apolygonal shape having two or more facets.

Each of the color filters 410 may have a square, diamond, rectangular orpolygonal shape. The color filters 410 and the light block units 430 mayhave a gap or tolerance of about 2 micrometers in order not to passareas of the color filters 410.

Accordingly, the edge lenses are not limited within the areas which donot pass the color filters 410 and may have a square, diamond,rectangular or polygonal shape.

When the edge lenses are formed, shapes thereof are not limited thereto.However, since the edge lenses are formed on the lower surface of thecolor filter layer 400, the shape of the color filter layer 400 may beaffected. That is, the edge lenses have a polygonal shape having two ormore facets, and the edge lens units 500 may be formed due to aninfluence of the color filter layers 400.

Hereinafter, the shape of the edge lens of FIG. 2 will be described indetail.

The heights h of the edge lenses may be from about 1 to about 5micrometers.

The edge lenses are formed on the lower surface of the color filterlayer 400, and the heights h of the edge lenses may not contact theencapsulation layer 300 because the color filter layer 400 and theencapsulation layer 300 are bonded by the bonding area 600.

Thus, if the heights h of the edge lenses are from about 1 to about 5micrometers, the efficiency may be maximized, but the heights h of theedge lenses are not limited thereto.

The widths W of the edge lenses may be between 2 micrometers and half ofwidths x of the color filters 410.

Since the edge lenses are formed on the edges of the light block units430 and the color filters 410, the edge lenses may be formed on edges oftwo light block units 430 adjacent to one color filter 410 as describedabove. Accordingly, the widths W of the edge lenses may be limited.

As shown in FIG. 2, when two edge lenses are formed on each of the lowersurfaces of the color filters 410, the sum of the widths 2 of the edgelenses may be equal to or smaller than the widths x of the color filters410.

Therefore, the widths w of the edge lenses may be a half of maximumwidths x of the color filters 410. For example, if the widths w of theedge lenses are greater than or equal to about 4 micrometers and lessthan or equal to about 18 micrometers, the efficiency of the OLEDdisplay may be maximized.

However, the widths w of the edge lenses are not limited thereto, and ifthe widths w of the edge lenses may be between about 2 micrometers andhalf of the widths x of the color filters 410, the widths w of the edgelenses are not limited to a certain number.

Initial angle θ of the edge lenses may be in a range from about 40degrees to about 90 degrees. The initial angle θ of the edge lenses maybe determined according to the heights h and widths w of the edgelenses, but are not limited thereto. The initial angle θ of the edgelenses may be determined to maximize the efficiency of the OLED display.

The OLED display according to the present embodiment may maximize thelight efficiency by adjusting the initial angle θ, heights h and widthsof the edge lenses within a range capable of forming the edge lenses.

FIG. 4 is a schematic diagram of an OLED display according to anotherembodiment of the present invention, and FIG. 5 is a diagram of anenlarged portion of the OLED display of FIG. 4.

As shown in FIG. 4, the OLED display may further include light diffusionlens units 700 formed above the color filter layer 400.

Each of the light diffusion lens units 700 may include a light diffusionlens which diffuses light generated and emitted by the organiclight-emitting devices 200 and may be convex in a light emissiondirection.

The light diffusion lens unit 700 may include at least one lightdiffusion lens, and the at least one light diffusion lens may be formedon each of the color filters 410.

In some embodiments, the light diffusion lens units 700 are formed onlyin the color filters 410 unlike the edge lens units 500 which are notformed only on the lower surfaces of the color filters 410 but formedbetween the lower surfaces of the color filters 410 and those of thelight block units 430 adjacent to the color filters 410.

The light diffusion lens units 700 are respectively formed in the colorfilters 410, and as shown in FIG. 4, three light diffusion lenses may beincluded in one sub-pixel, but the present invention is not limitedthereto.

Since the OLED display according to the present embodiment may includethe edge lens units 500 on the lower surface of the color filter layer400 and the light diffusion lens units 700 on the upper surface of thecolor filter layer 400, the light efficiency may be more improved.

External light can be refracted and reflected in the OLED display by theedge lens unit 500, and the reflected light can be absorbed by the lightblock units 430. Thus, the reflection may be reduced and light emittedfrom the organic light-emitting device 200 to the outside may bediffused and emitted by the light diffusion lens unit 700.

Therefore, the light efficiency of the OLED display may be improved moreby preparing both the edge lens units 500 and the light diffusion lensunit 700. The emitted light is diffused, and thus, degradation ofvisibility at sides may be corrected. That is, side visibility (WAD) maybe improved.

The edge lenses included in the edge lens units 500 and the lightdiffusion lenses included in the light diffusion lens units 700 may beformed of organic materials having a high refractive index.

As described above, the edge lenses are formed of the organic materialshaving the refractive index higher than the refractive index of anorganic material which fills the bonding area 600, and thus, externallight may be effectively refracted and reflected in the OLED display.

Also, the light diffusion lenses may be formed of the organic materialshaving the high refractive index in order to make light be effectivelydiffused to the upper surface of the color filter layer 400 due torefraction of the light.

FIG. 5 is a diagram of an enlarged portion of the OLED display accordingto another embodiment. FIG. 5 shows one light block unit 430 adjacent toone of the color filters 410 and a lens unit formed on an upper surfaceand a lower surface of the color filter layer 400.

The light diffusion lens formed on the upper surface of the color filterlayer 400 may have a height “a” of at least about 1 micrometer. Sincethe light diffusion lens is formed to allow light emitted from the OLEDdisplay to be refracted and diffused, and light diffusion lens may havea height “a” of at least about 1 micrometer.

The height a of the light diffusion lens may not be limited unlike theedge lenses formed on the lower surface of the color filter layer 400.Since the light diffusion lens is formed on the upper surface of thecolor filter layer 400, the light diffusion lens may not contact othercomponents such as the encapsulation layer 300 unlike the edge lens.

As shown in FIG. 5, the width b of each of the edge lens formed on theOLED display may be between about 2 micrometers and about a third of thewidth x of a color filter.

As shown in FIG. 5, widths of the edge lenses formed on the lowersurface of the color filter layer 400 and those of the light diffusionlenses formed on the upper surface of the color filter layer 400 may notoverlap.

That is, the edge lenses are formed on edges of the light block units430 and some of the color filters 410, and the light diffusion lensesare formed in the color filters 410 in order not to overlap the edgelenses.

If the edge lens units 500 formed on the lower surface of the colorfilter layer 400 and the light diffusion lens units 700 formed on theupper surface thereof overlap, a path, via which light that is refractedpasses, is disturbed and light efficiency may be decreased.

Therefore, as shown in FIG. 5, if two edge lenses are formed on thelower surface of the color filter layer 400 and one light diffusion lensis formed on the upper surface thereof in order not to make the widthsof the edge lenses and light diffusion lens overlap on a color filter410, the sum of the widths of three lenses, that is, two edge lenses andthe light diffusion lens, may be the same as a width x of the colorfilter 410.

In this case, each lens may not overlap each other, and since the sum ofthe widths of three lenses is the same as the width x of the colorfilter 410, a width of each lens may be about a third of the width x ofthe color filter 410.

Therefore, the width b of each edge lens may be a half of the width x ofthe color filter 410 at most. In some embodiments, when the width b ofeach edge lens is in a range from about 4 micrometers to about 18micrometers, the efficiency of the OLED display may be maximized.

However, the length of the width b of each edge lens is not limitedthereto. If the length of the width b of each edge lens is betweenmicrometers 2 micrometers and about a third of the width x of the colorfilter 410, the length of the width b may not be limited to a certainrange.

Descriptions regarding shapes of lenses other than the above detaileddescriptions are the same as descriptions regarding the OLED displayaccording to the above embodiment of the present invention. That is,since descriptions regarding the height h and initial angle θ of theedge lens are already provided, descriptions will not be repeated forconvenience of explanation.

FIG. 6 is a schematic diagram of an OLED display according to anotherembodiment.

In the OLED display according to the present embodiment, the lightdiffusion lens unit 700 formed on the upper surface of the color filterlayer 400 may include at least two light diffusion lenses in each colorfilter 410.

As shown in FIG. 6, three light diffusion lenses may be formed on anupper portion of each color filter 410.

That is, the edge lens unit 500 may be formed on the lower surface ofthe color filter layer 400, and the light diffusion lens unit 700 may beformed on the upper surface of the color filter layer 400. The lightdiffusion lens unit 700 may have nine light diffusion lenses in eachsub-pixel.

The number of light diffusion lenses is not limited to the abovedescription, and nine or more light diffusion lenses may be included inone sub-pixel.

When multiple light diffusion lenses are included, the width of eachlight diffusion lens may be small, and as shown in FIG. 6, the widths ofthe light diffusion lenses and those of the edge lenses may overlap.However, the present embodiment is not limited thereto, and the widthsof the light diffusion lenses and those of the edge lenses may notoverlap. In this case, the length of the width of each light diffusionlens may be much small.

When multiple light diffusion lenses are formed as in the OLED displayaccording to the present embodiment, light emitted from the organiclight-emitting device 200 is rather effectively diffused, and thus aproblem regarding the side visibility (WAD) may be corrected.

Each of the components of the OLED display shown in FIG. 6 has the samestructure and effects as the components that are already described, andthus, descriptions regarding the components of the OLED display will notbe repeated.

According to a method of manufacturing the OLED display according to thepresent embodiment, an organic light-emitting device 200 including aplurality of pixels emitting different colors of light may be formed onthe substrate 100 as shown in FIG. 6.

When the organic light-emitting device 200 is formed on the substrate100, an encapsulation layer 300 may be formed on an upper surface of theorganic light-emitting device 200 in order to encapsulate the organiclight-emitting device 200 to prevent the organic light-emitting device200 from light and moisture.

Then, a color filter layer 400 formed on an upper surface of theencapsulation layer 300 may be formed. The color filter layer 400 mayinclude color filters 410 formed on areas corresponding to pixels, andlight block units 430 respectively formed between the lower surfaces ofthe color filters 410.

Edge lens units 500 which are formed on a lower surface of the colorfilter layer 400 and formed between the lower surfaces of the colorfilters and those of the light block units 430 may be formed.

A bonding process, via which the organic light-emitting device 200 whichis encapsulated by the encapsulation layer 300 is bonded to the lowersurface of the color filter layer 400 on which the edge lens units 500are formed, may be performed.

According to the method of manufacturing the OLED display according tothe present embodiment, a bonding area where the color filter layer 400and the encapsulation layer 300 are bonded may be substantially filledwith air in the bonding process.

Since air has a refractive index smaller than that of the edge lensunits 500, external light may be refracted when the external lightpasses edge lenses and penetrates the air, and also, the refracted lightmay be absorbed by the light block units 430 due to the reflection,thereby decreasing reflection of the external light.

According to some embodiments, a bonding area where a color filter layer400 and an encapsulation layer 300 are bonded may be substantiallyfilled with an organic material having a low refractive index and thenbonded.

In this case, edge lens units 500 may be formed of an organic materialhaving a high refractive index. Since a bonding area 600 formed on lowerportions of the edge lens units 500 are substantially filled with anorganic material having a refractive index that is lower than arefractive index of the edge lenses, reflection and refraction ofexternal light may occur when the external light enters, and thus, thereflection of the external light may be decreased.

As described above, according to at least one of the disclosedembodiments, an OLED display having improved brightness of an entirescreen and side viewing angles can be provided.

It should be understood that the exemplary embodiments described thereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While the inventive technology has been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the present invention as definedby the following claims.

What is claimed is:
 1. An organic light-emitting diode (OLED) displaycomprising: a substrate; an OLED on the substrate, the OLED comprising afirst electrode, a second electrode facing the first electrode, and anemitting layer therebetween; an encapsulation section over the OLED andcomprising at least one inorganic layer and at least one organic layer;and a refractive section comprising: a first refractive index layerlocated over the encapsulation section; and a second refractive indexlayer located over the first refractive index layer and including aportion that protrudes toward the encapsulation section, wherein thefirst refractive index layer has a first refractive index, and thesecond refractive index layer has a second refractive index that isgreater than the first refractive index, and wherein an upper surface ofthe refractive section is flat.
 2. The OLED display of claim 1, whereinthe second refractive index layer is in direct contact with the firstrefractive index layer.
 3. The OLED display of claim 1, wherein theportion of the second refractive index layer overlaps a portion of theOLED.
 4. The OLED display of claim 1, wherein an upper surface of thesecond refractive index layer is located on a same plane as the uppersurface of the refractive section.
 5. The OLED display of claim 1,wherein the first refractive index layer comprises an organic material.6. The OLED display of claim 1, wherein the second refractive indexlayer comprises an organic material.
 7. The OLED display of claim 1,wherein the portion of the second refractive index layer has an inclinedsurface that is inclined with respect to the upper surface of therefractive section.
 8. The OLED display of claim 7, wherein an initialangle of the inclined surface is in a range from about 40 degrees toabout 90 degrees.
 9. An organic light-emitting diode (OLED) displaycomprising: an OLED comprising a first electrode, a second electrodefacing the first electrode, and an emitting layer therebetween; anencapsulation section over the OLED and comprising at least oneinorganic layer and at least one organic layer; and a refractive sectioncomprising: a first refractive index layer located over theencapsulation section; and a second refractive index layer located overthe first refractive index layer and including a portion that protrudestoward the encapsulation section and that overlaps a portion of theOLED, wherein the first refractive index layer has a first refractiveindex, and the second refractive index layer has a second refractiveindex that is greater than the first refractive index, and. wherein thesecond refractive index layer is in direct contact with the firstrefractive index layer.
 10. The OLED display of claim 9, wherein anupper surface of the second refractive index layer is located on a sameplane as an upper surface of the refractive section.
 11. The OLEDdisplay of claim 9, wherein an upper surface of the refractive sectionis flat.
 12. The OLED display of claim 11, wherein the portion of thesecond refractive index layer has an inclined surface that is inclinedwith respect to the an upper surface of the refractive section.
 13. TheOLED display of claim 12, wherein an initial angle of the inclinedsurface is in a range from about 40 degrees to about 90 degrees.
 14. TheOLED display of claim 9, wherein the first refractive index layercomprises an organic material.
 15. The OLED display of claim 9, whereinthe second refractive index layer comprises an organic material.